Napier Technical College opened in 1964 to plug a gap in Scotland's industrial education. The opening ceremony took place on 23 February 1965. In 1966 the name lengthened to Napier College of Science and Technology; in 1974 it absorbed the Edinburgh College of Commerce out at Sighthill and became Napier College of Commerce and Technology. The Scottish Education Department made it a Central Institution - effectively a polytechnic - in 1985. The next year it took over the cavernous baronial buildings at Craiglockhart, on a hill above the Water of Leith. In June 1992, watched by 700 staff and students, the Conservative minister Lord James Douglas-Hamilton and the principal William Turmeau unveiled a sign that said Napier University. In February 2009 it added Edinburgh to the front. The motto is Nisi sapientia frustra - without knowledge, all is in vain - and the university launched its own tartan that same year.

Merchiston Castle, the 15th-century L-plan tower house where John Napier was born, sits in the geographic centre of the main campus. It is Category A listed - the top tier of Scottish architectural protection - and the seat of Clan Napier. The Schools of Art and Creative Industries and of Computing, Engineering and the Built Environment grew up around the refurbished shell. Inside the campus stands the 500-seat Jack Kilby Computing Centre, named for the American engineer who invented the integrated circuit and the handheld calculator - a fitting neighbour to the man who, four hundred years earlier, invented the calculating method Kilby's devices eventually mechanised. The campus also houses a computer game laboratory, professional music studios, and a broadcast journalism newsroom officially opened in 2016 by alumna and TV presenter Lorraine Kelly.

The Craiglockhart campus has a darker inheritance. Originally a Victorian Hydropathic hotel - one of the spa-and-cold-water-cure resorts that flourished in the 19th century - the building was requisitioned during the First World War as a hospital for officers diagnosed with shell shock. Wilfred Owen was treated here from June 1917, and met fellow officer-poet Siegfried Sassoon in the same wards. They edited the hospital magazine, The Hydra. Owen's first major poem, Dulce et Decorum Est, was drafted here. Sassoon, already famous as a war poet, encouraged Owen to push deeper. Owen returned to the front in 1918 and was killed a week before the Armistice. The campus now hosts the Business School, with two lecture theatres, a War Poets Collection exhibition opened in 2005 by the BBC correspondent Allan Little, and photographs of the patients and staff who passed through during those few terrible years.

The Sighthill campus, opened in January 2011, holds the schools of Health and Social Care and Applied Sciences. The five-storey learning resource centre, clinical skills suite, and IT-enabled lecture theatres earned a BREEAM Excellent rating for sustainable design. The sports facility includes an environmental chamber that can simulate high-altitude or polar conditions, with controllable temperature and humidity - useful for athletes, useful for the Scottish Rugby Academy that has trained at Sighthill since 2016. Across all three campuses the university now teaches over 21,000 students, including nearly 9,500 international and EU students from more than 140 countries. The principal since January 2025 is Sue Rigby; the chancellor is Will Whitehorn, the Edinburgh-born former Virgin Group executive who heads the UK space industry trade body.

Napier has won the Queen's Anniversary Prize twice: in 2009 for work improving sound insulation in attached housing, and in 2015 for timber engineering, sustainable construction and wood science. Its research centres span sustainable construction, transport, distributed computing and security, mountain biking, the book industry, and timber engineering. In 2018 the university launched the Blockpass Identity Lab to research blockchain identity systems. In 2023 it set up The SurfLab in partnership with Lost Shore - Scotland's first inland surf resort, opened the year after - to research surf therapy, performance, and wetsuit testing. The Scottish Institute for Policing Research, a collaboration with Police Scotland and fourteen other Scottish universities, is hosted here. In its 2025 international ratings, Napier sat between 501 and 600 in the Times Higher Education world rankings and earned five stars from QS Stars for teaching, employability and internationalisation.